1 files changed, 106 insertions, 4 deletions

diff --git a/tools/perf/builtin-test.c b/tools/perf/builtin-test.c
index 035b9fa063a..1c984342a57 100644
--- a/tools/perf/builtin-test.c
+++ b/tools/perf/builtin-test.c
@@ -119,10 +119,16 @@ static int test__vmlinux_matches_kallsyms(void)
          * end addresses too.
          */
         for (nd = rb_first(&vmlinux_map->dso->symbols[type]); nd; nd = rb_next(nd)) {
-                struct symbol *pair;
+                struct symbol *pair, *first_pair;
+                bool backwards = true;
 
                 sym  = rb_entry(nd, struct symbol, rb_node);
-                pair = machine__find_kernel_symbol(&kallsyms, type, sym->start, NULL, NULL);
+
+                if (sym->start == sym->end)
+                        continue;
+
+                first_pair = machine__find_kernel_symbol(&kallsyms, type, sym->start, NULL, NULL);
+                pair = first_pair;
 
                 if (pair && pair->start == sym->start) {
 next_pair:
@@ -143,8 +149,10 @@ next_pair:
                                 pr_debug("%#Lx: diff end addr for %s v: %#Lx k: %#Lx\n",
                                          sym->start, sym->name, sym->end, pair->end);
                         } else {
-                                struct rb_node *nnd = rb_prev(&pair->rb_node);
-
+                                struct rb_node *nnd;
+detour:
+                                nnd = backwards ? rb_prev(&pair->rb_node) :
+                                                  rb_next(&pair->rb_node);
                                 if (nnd) {
                                         struct symbol *next = rb_entry(nnd, struct symbol, rb_node);
 
@@ -153,6 +161,13 @@ next_pair:
                                                 goto next_pair;
                                         }
                                 }
+
+                                if (backwards) {
+                                        backwards = false;
+                                        pair = first_pair;
+                                        goto detour;
+                                }
+
                                 pr_debug("%#Lx: diff name v: %s k: %s\n",
                                          sym->start, sym->name, pair->name);
                         }
@@ -219,6 +234,89 @@ out:
         return err;
 }
 
+#include "util/evsel.h"
+#include <sys/types.h>
+
+static int trace_event__id(const char *event_name)
+{
+        char *filename;
+        int err = -1, fd;
+
+        if (asprintf(&filename,
+                     "/sys/kernel/debug/tracing/events/syscalls/%s/id",
+                     event_name) < 0)
+                return -1;
+
+        fd = open(filename, O_RDONLY);
+        if (fd >= 0) {
+                char id[16];
+                if (read(fd, id, sizeof(id)) > 0)
+                        err = atoi(id);
+                close(fd);
+        }
+
+        free(filename);
+        return err;
+}
+
+static int test__open_syscall_event(void)
+{
+        int err = -1, fd;
+        struct thread_map *threads;
+        struct perf_evsel *evsel;
+        unsigned int nr_open_calls = 111, i;
+        int id = trace_event__id("sys_enter_open");
+
+        if (id < 0) {
+                pr_debug("is debugfs mounted on /sys/kernel/debug?\n");
+                return -1;
+        }
+
+        threads = thread_map__new(-1, getpid());
+        if (threads == NULL) {
+                pr_debug("thread_map__new\n");
+                return -1;
+        }
+
+        evsel = perf_evsel__new(PERF_TYPE_TRACEPOINT, id, 0);
+        if (evsel == NULL) {
+                pr_debug("perf_evsel__new\n");
+                goto out_thread_map_delete;
+        }
+
+        if (perf_evsel__open_per_thread(evsel, threads) < 0) {
+                pr_debug("failed to open counter: %s, "
+                         "tweak /proc/sys/kernel/perf_event_paranoid?\n",
+                         strerror(errno));
+                goto out_evsel_delete;
+        }
+
+        for (i = 0; i < nr_open_calls; ++i) {
+                fd = open("/etc/passwd", O_RDONLY);
+                close(fd);
+        }
+
+        if (perf_evsel__read_on_cpu(evsel, 0, 0) < 0) {
+                pr_debug("perf_evsel__open_read_on_cpu\n");
+                goto out_close_fd;
+        }
+
+        if (evsel->counts->cpu[0].val != nr_open_calls) {
+                pr_debug("perf_evsel__read_on_cpu: expected to intercept %d calls, got %Ld\n",
+                         nr_open_calls, evsel->counts->cpu[0].val);
+                goto out_close_fd;
+        }
+        
+        err = 0;
+out_close_fd:
+        perf_evsel__close_fd(evsel, 1, threads->nr);
+out_evsel_delete:
+        perf_evsel__delete(evsel);
+out_thread_map_delete:
+        thread_map__delete(threads);
+        return err;
+}
+
 static struct test {
         const char *desc;
         int (*func)(void);
@@ -228,6 +326,10 @@ static struct test {
                 .func = test__vmlinux_matches_kallsyms,
         },
         {
+                .desc = "detect open syscall event",
+                .func = test__open_syscall_event,
+        },
+        {
                 .func = NULL,
         },
 };